Broadcasting is a well-known and well-received method of communication for transfer of information. Broadcasting enables transfer of both audio and visual information, depending upon the need and capability of the broadcaster.
Conventionally, frequency modulation (FM) or amplitude modulation (AM) has been used to broadcast audio information over a wide geographical region. FM or AM channels for broadcast are limited in that only audio signals can be transmitted. Audio signals as information or entertainment have a temporary effect on the listener's memory. Further, the temporary information may impose a cognitive load on the listener's memory. To reduce the temporary effect of audio signals on the listener's memory, audio signals may be combined with visual signals as in the case of television broadcasting, though separate channels are needed for broadcasting the audio and visual signals.
Another method of broadcasting information is Cell Broadcast (CB) for mobile phones, however CB is restricted to certain text-only types of broadcast, thereby limiting its usability. Another method for broadcasting to cell phones is Bluetooth™, but that method has security restrictions, as well as timing and visibility constraints, thereby rendering the technology ineffective to achieve maximum penetration in a given locality.